#include "myiic.h"
#include "delay.h"
 
//???IIC
void IIC_Init(void)
{			
  GPIO_InitTypeDef  GPIO_InitStructure;
 
  RCC_AHB1PeriphClockCmd(RCC_AHB1Periph_GPIOB, ENABLE);//??GPIOB??
 
  //GPIOB8,B9?????
  GPIO_InitStructure.GPIO_Pin = GPIO_Pin_8 | GPIO_Pin_9;
  GPIO_InitStructure.GPIO_Mode = GPIO_Mode_OUT;//??????
  GPIO_InitStructure.GPIO_OType = GPIO_OType_PP;//????
  GPIO_InitStructure.GPIO_Speed = GPIO_Speed_100MHz;//100MHz
  GPIO_InitStructure.GPIO_PuPd = GPIO_PuPd_UP;//??
  GPIO_Init(GPIOB, &GPIO_InitStructure);//???
	IIC_SCL=1;
	IIC_SDA=1;
}
//??IIC????
void IIC_Start(void)
{
	SDA_OUT();     //sda???
	IIC_SDA=1;	  	  
	IIC_SCL=1;
	delay_us(4);
 	IIC_SDA=0;//START:when CLK is high,DATA change form high to low 
	delay_us(4);
	IIC_SCL=0;//??I2C??,????????? 
}	  
//??IIC????
void IIC_Stop(void)
{
	SDA_OUT();//sda???
	IIC_SCL=0;
	IIC_SDA=0;//STOP:when CLK is high DATA change form low to high
 	delay_us(4);
	IIC_SCL=1; 
	IIC_SDA=1;//??I2C??????
	delay_us(4);							   	
}
//????????
//???:1,??????
//        0,??????
u8 IIC_Wait_Ack(void)
{
	u8 ucErrTime=0;
	SDA_IN();      //SDA?????  
	IIC_SDA=1;delay_us(1);	   
	IIC_SCL=1;delay_us(1);	 
	while(READ_SDA)
	{
		ucErrTime++;
		if(ucErrTime>250)
		{
			IIC_Stop();
			return 1;
		}
	}
	IIC_SCL=0;//????0 	   
	return 0;  
} 
//??ACK??
void IIC_Ack(void)
{
	IIC_SCL=0;
	SDA_OUT();
	IIC_SDA=0;
	delay_us(2);
	IIC_SCL=1;
	delay_us(2);
	IIC_SCL=0;
}
//???ACK??		    
void IIC_NAck(void)
{
	IIC_SCL=0;
	SDA_OUT();
	IIC_SDA=1;
	delay_us(2);
	IIC_SCL=1;
	delay_us(2);
	IIC_SCL=0;
}					 				     
//IIC??????
//????????
//1,???
//0,???			  
void IIC_Send_Byte(u8 txd)
{                        
    u8 t;   
	SDA_OUT(); 	    
    IIC_SCL=0;//??????????
    for(t=0;t<8;t++)
    {              
        IIC_SDA=(txd&0x80)>>7;
        txd<<=1; 	  
		delay_us(2);   //?TEA5767??????????
		IIC_SCL=1;
		delay_us(2); 
		IIC_SCL=0;	
		delay_us(2);
    }	 
} 	    
//?1???,ack=1?,??ACK,ack=0,??nACK   
u8 IIC_Read_Byte(unsigned char ack)
{
	unsigned char i,receive=0;
	SDA_IN();//SDA?????
    for(i=0;i<8;i++ )
	{
        IIC_SCL=0; 
        delay_us(2);
		IIC_SCL=1;
        receive<<=1;
        if(READ_SDA)receive++;   
		delay_us(1); 
    }					 
    if (!ack)
        IIC_NAck();//??nACK
    else
        IIC_Ack(); //??ACK   
    return receive;
}
 